Refrigerating apparatus for boats and automobiles



April 25, 1967 A. HEATON REFRIGERATING APPARATUS FOR BOATS AND AUTOMOBILES 2 Sheets-Sheet 1 Filed July 2, 1965 Tiuilillflllil.

Apnl 25, 1967 A. HEATON 3,3 7

REFRIGERATING APPARATUS FOR BOATS AND AUTOMOBILES- Filed July 2, 1965 2 Sheets-Sheet 2 .Laaaaa diHeaibiq by L11. Q 7AM.

floiioviaeg United States Patent 3,315,487 REFRIGERATING APPARATUS FOR BOATS AND AUTOMOBILES Lance A. Heaton, Boston, Mass. (30 Beach Road, Apt. 3B, Middle River, Md. 21220) Filed July 2, 1965, Ser. No. 469,190 1 Claim. (Cl. 62-226) This invention relates to refrigerating apparatus and pertains more particularly to refrigerating apparatus for motor boats and for automobiles such as camping vehicles.

The principal purpose of the invention is to provide a compact and relatively inexpensive refrigerating system which may be easily installed in connection with the usual ice box of a cruising sailboat, with the ice box or refrigerator of a power cruiser, or with the ice box or refrigerator of an automobile designed for family cruising and camping, and which comprises a compressor unit operated by the marine engine or the engine of the motor vehicle.

A particular object of the invention is to provide mechanical refrigerating apparatus having a food storage compartment which may be cooled to a temperature of approximately 3640 F. by operating the compressor for approximately 20 minutes and maintained at food storage temperature for at least 24 hours; and a freezing compartment for ice cubes or the like which may be cooled to a temperature of approximately 15 F. by operating the compressor for about minutes, and maintain frozen ice cubes for many hours without reactivating the compressor.

A further object involves the construction of the freezing compartment which may be installed within or closely adjacent the food storage compartment and which is preferably formed with a flat bottom having spaced double walls and double, spaced side walls, so that the compressed and liquified refrigerant may circulate between the double walls of the frozen compartment and boil therein to ensure rapid freezing of the ice cubes therein.

These and other advantages of the improved refrigerating system will become apparent from the following description of the recommended embodiments of the invention, as illustrated on the accompanying drawings; but it will be understood that the structural details of said embodiments may be varied to suit particular conditions without departing from the essence of the invention, as set forth in the appended claim.

In the drawings,

FIG. 1 is a diagrammatic view of the improved refrigerating system as installed in an auxiliary sailboat having a conventional ice box for food storage, and a standard marine engine;

FIG. 2 is an enlarged sectional perspective view of the freezing compartment as shown in FIG. 1; and

FIG. 3 is an elevation of a modified arrangement in which the freezing compartment is located centrally of the brine tank in the food storage compartment of the ice box.

In the form chosen for the purpose of illustration in FIG. 1, the refrigerating apparatus comprises a compressor unit 11 driven by a belt 12, or otherwise, from the auxiliary marine engine (not shown) of the cruising sailboat through a standard electro-magnetic clutch 13, a receiver-condenser 14 which is cooled by sea water of the engine cooling system passing through a by-pass pipe line 15 suitably associated with the condenser; conduits 16 and 17 connected respectively between the compressor and the condenser, and between the condenser and an expansion valve 18; a conduit 19 leading from the expansion valve to the double walled freezing compartment 20; a conduit 21 leading from the freezing compartment to the coils 22 of a eutectic brine tank 23; and a conduit 24 leading from said coils back to the compressor 11.

The compressor is preferably a high speed standard unit, turning at 1500 to 2500 r.p.m. as sold under the trade name York or Tecumseh, absorbing from 4 to 7 horsepower; and the clutch 13 is designed to cooperate with the selected compressor, such as a standard unit marketed under the trade name Borg-Warner. The thermostatic expansion valve 18 is also a conventional and available unit for refrigerating systems; and that valve is wired by line 25 to a thermostatic control 26 adjacent the brine tank.

The refrigerant circulated through this flooded system is preferably Freon 12 which has a freezing point at 22 /2 below zero F. at zero pressure; and the anti-freeze liquid in the brine tank is preferably a 15% by weight solution of propylene glycol in water, which is non-toxic and non-corrosive.

The gaseous Freon, compressed in the compressor 11 circulates through conduit 16 as a high pressure, superheated vapor, but is liquified in the condenser 14 and loses pressure at the expansion valve 18, so that it is fed to the freezing compartment 20 as a relatively low pressure liquid and/ or very wet gas. As the liquid or wet gaseous refrigerant circulates through the spaced double walls of the compartment 20, it absorbs heat therefrom and boils, quickly reducing the temperature of the freezing compartment and freezing the water in the ice cube trays (not shown) located therein.

, The refrigerant then circulates as a wet gas from the freezing compartment, through conduit 21 to the coils 22 in the brine tank 23. The coils 22 are preferably spaced no more than 2 inches apart so that the anti-freeze solution in the tank becomes solidly frozen within 20 to 30 minutes after the compressor starts operating. The tank 23 is preferably of stainless steel and occupies a space in the ice box, indicated by broken lines 26, which would normally be occupied by a block of ice placed in the food storage compartment of the box. The precise location of the tank depends upon the size and shape of the interior of the ice box in which it is installed.

The food freezing compartment is preferably made of copper, and it is desirable that the ice trays placed therein be also of copper to ensure rapid heat transfer.

As shown in FIG. 1 and to enlarged scale in FIG. 2, the freezer compartment is mounted by suspension straps 27 or otherwise against the bottom of tank 23, so that it helps to keep the tank liquid frozen; whereas, in FIG. 3, the compartment 20 is suitably installed in the center of the tank. Other locations are obviously possible, but it is desirable that the freezing compartment be disposed close to or within the tank 23, and in such a position that ice cube trays may be slid in and out of the compartment.

As best shown in FIG. 3, the compartment 20 is designed to receive two ice trays and is formed to provide fiat bottom surfaces 28 to receive such trays which preferably also have flat bottoms for adequate heat transfer. The bottom of the compartment is double-walled, having a seamed wall 29 spaced below the walls 28, to provide an intervening space 30 for the circulating refrigerant entering through conduit 19. The compartment also has double-walled sides 31 and 32 affording similar spaces, and a double-walled longitudinal partition 33 defining the areas for two ice cube trays, although it is apparent that the compartment may be designed to contain more or less than two trays.

The spaced bottom walls 28 and 29 are preferably braced by rivets 34 or other spacing elements to prevent expansion thereof under pressure of the circulating refrigerant in the space 30.

The compressor 11 may be automatically activated and deactivated, while the power source continues to run, by providing a temperature control box 35 connected by a line 36 to a temperature sensor 37 located in the brine 4 a tank 23, and wired to the electro-magnetic clutch 13 by line 38, to provide a thermostatic control. Thus, when the brine tank solution is frozen, the clutch Will disengage to deactivate the compressor, and will re-engage to activate the compressor when the temperature in the brine tank rises.

A manual switch 38 may also be provided for controlling the engagement of the clutch 13.

The refrigerating system above described may be installed in connection With the marine engine and ice box of most cruising sailboats and admirably achieves the objects of this invention for marine use, avoiding the necessity of frequently purchasing block ice for the con ventional ice box, and also avoiding the necessity of providing high powered generatorsfor operation of an electric refrigerator. Moreover, the storage compartment will be maintained at a lower temperature than would be afforded by a comparable block of ice; and the hold-over time will be substantially as long as that afforded by an equivalent block of ice; the absolute hold-over period depending on the efficiency of the insulation of the ice box or refrigerator, and the frequency of openings of the ice box latch.

The spaced double walls of the freezer compartment accommodate a heavy volume of rapidly circulating refrigerant to ensure quick freezing of ice cubes. The spacing between the bottom and vertical walls may vary from /2 inch to inch, but the distance is not critical so long as the space area is adequate to contain a large volume of the refrigerant.

For use in cruising or camping motor vehicles, an air cooled condenser is used in place of the water cooled condenser in marine use; and the condenser 14 is preferably substituted by a dryer and receiver-condenser of conventional type when the improved system is installed in an automobile,

I claim:

Mechanical refrigerating apparatus for boats and automobiles having an engine and a box to be refrigerated, comprising a compressor mechanically coupled to and driven by the engine, a condenser, an expansion valve, and a freezing compartment for ice cube trays, a brine tank, a conduit for refrigerant interconnectingthe compressor, the condenser, the valve and said compartment and said brine tank, said brine tank and compartment being located in the box and the box providing a food storage compartment, a conduit for refrigerant leading from said compartment into said brine tank and back to said compressor, and clutch means intermediate the engine and the compressor; thermostatic control means for regulating the operation of the clutch and for regulating the operation of the expansionvalve in accordance with the temperature in the brine tank; said freezing compartment having a doublewalled bottom and double-walled sides providing communicating spaces between said walls for the circulation of liquid refrigerant through said spaces and thence to the brine tank conduit, and means for circulating refrigerant through said spaces; and spacing means between the respective Walls of said bottom for holding said walls in sub-- stantially parallel, spaced relation against pressures created in the space between them.

References Cited by the Examiner Ammons 62436 MEYER PERLIN, Primary Examiner. V 

